{"id":774,"date":"2026-06-23T09:46:59","date_gmt":"2026-06-23T09:46:59","guid":{"rendered":"https:\/\/oldhamcoupling.net\/product\/sl240-industrial-oldham-coupling\/"},"modified":"2026-06-24T08:47:43","modified_gmt":"2026-06-24T08:47:43","slug":"sl240-industrial-oldham-coupling","status":"publish","type":"product","link":"https:\/\/oldhamcoupling.net\/nl\/product\/sl240-industrial-oldham-coupling\/","title":{"rendered":"SL240 Industrial Oldham Coupling"},"content":{"rendered":"
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SL240 Heavy-Industrial Cross-Slider Oldham Coupling \u2014 240 mm Cast-Iron Hub for Cement-Mill Main and Steel-Mill Auxiliary Drives<\/h2>\n

The SL240 industrial Oldham coupling<\/strong> moves the SL family firmly into the heavy industrial drive class. With 8 000 N\u00b7m rated torque, 240 mm hub OD, 95\u2013100 mm bore range, and 250 r\/min permissible speed, the SL240 transmits 150\u2013210 kW of continuous mechanical power. This is the duty class of cement-mill main drives, hot-strip-mill auxiliary lines, larger hydropower-auxiliary trains, and the heaviest process-pump installations in the chemical, petrochemical, and metallurgical industries. At this scale the coupling is unambiguously a critical-asset component; specification involves a multi-discipline engineering review, and the deployment is expected to operate reliably across multiple cycles of host-equipment overhaul.<\/p>\n

For the integrator specifying a coupling at this size, the engineering question moves beyond “which architecture is best for steady-state torque” to encompass three additional concerns: shock-load endurance over decades of duty, serviceability of wear parts during constrained planned-shutdown windows, and predictability of failure modes for maintenance-planning purposes. The SL240 addresses all three through its architecture. Cast-iron hub section provides shock-load capacity. Field-replaceable hardened-steel slider provides serviceability. And the gradual, inspectable wear mechanism delivers the predictable failure profile that maintenance planning depends on. These three structural advantages \u2014 invariant across the SL family \u2014 become especially valuable at the SL240’s power level.<\/p>\n

Specifications<\/h3>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
Model<\/td>\nSL240<\/td>\n<\/tr>\n
Nominal Torque (Tn)<\/td>\n8 000 N\u00b7m<\/td>\n<\/tr>\n
Permissible Speed (n)<\/td>\n250 r\/min<\/td>\n<\/tr>\n
Bore Range (d)<\/td>\n95 \u2013 100 mm<\/td>\n<\/tr>\n
Outside Diameter (D)<\/td>\n240 mm<\/td>\n<\/tr>\n
Hub Bore Diameter (D\u2081)<\/td>\n140 mm<\/td>\n<\/tr>\n
Overall Length (L)<\/td>\n180 mm<\/td>\n<\/tr>\n
Slider Plate Thickness (H)<\/td>\n33 mm<\/td>\n<\/tr>\n
Slider Clearance (S)<\/td>\n1.0 mm<\/td>\n<\/tr>\n
Moment of Inertia<\/td>\n1.6 kg\u00b7m\u00b2<\/td>\n<\/tr>\n
Mass<\/td>\n59.5 kg<\/td>\n<\/tr>\n
Radial Misalignment (\u0394y)<\/td>\n3.8 mm<\/td>\n<\/tr>\n
Angular Misalignment (\u0394\u03b1)<\/td>\n0.5\u00b0<\/td>\n<\/tr>\n
Axial Misalignment (\u0394x)<\/td>\n3.0 mm<\/td>\n<\/tr>\n
Shaft Engagement<\/td>\nKeyway + setscrew<\/td>\n<\/tr>\n
Lubrication<\/td>\nGrease (re-pack 6-monthly)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\"SL240<\/p>\n

Materials<\/h3>\n
\n
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QT500-7 Ductile-Iron Hub (Standard at this Size)<\/h4>\n

At SL240 size and above, the QT500-7 ductile-iron hub variant is the documented standard specification, not just an upgrade option. The spheroidal-graphite microstructure’s superior fracture toughness addresses the dominant failure-risk vector at this duty class. HT250 grey-iron variant remains available for cost-sensitive light-duty installations, but engineering does not recommend it for cement-mill, steel-mill, or shock-load applications.<\/p>\n<\/p><\/div>\n

\n

Heavy Section Steel Slider<\/h4>\n

33 mm thick cross-slider in induction-hardened 45-steel or 40Cr alloyed steel. The slider’s mass (approximately 6 kg) becomes a noticeable engineering parameter at this size; reflected inertia at the motor is approximately 1.6 kg\u00b7m\u00b2. For reversal-duty deployments (steel-mill auxiliary, marine winches), the 40Cr alloy slider with HRC 55 surface is the documented specification.<\/p>\n<\/p><\/div>\n

\n

Heavy Industrial Mounting<\/h4>\n

H7-reamed bore with parallel keyway to GB\/T 1096. M20 set-screw for axial location. For cement-mill, steel-mill, and crusher applications, taper-bushed mounting via standard locking-assembly families is the documented engineering preferred approach \u2014 eliminating keyway shear under the realistic shock-load profile of these installations.<\/p>\n<\/p><\/div>\n<\/div>\n

Engineering Considerations for 150\u2013210 kW Drives<\/h3>\n

At this scale, the engineering calculus shifts: the SL240 is no longer competing primarily on unit cost \u2014 it is competing on lifecycle reliability and on the consequence cost of failure. A single unplanned shutdown of a 200 kW cement-mill main drive in a continuous-production plant typically costs more in lost production than the entire purchase price of the coupling several times over. Selection decisions are therefore driven by failure-mode analysis as much as by performance specification. On this front the SL240 has two structural advantages over competing flexible-coupling families at this size.<\/p>\n

First, the failure mode is gradual wear of a non-energy-storing metallic element. The polymer-spider failure mode (sudden tearing of the elastomer) does not apply. The flexible-disc-pack failure mode (sudden fracture of fatigue-damaged discs) does not apply. The fluid-coupling failure mode (loss of fluid charge) does not apply. The SL240 fails by gradual slot-edge wear of the cast-iron hub and gradual face wear of the steel slider, both of which are inspectable during routine maintenance and replaceable during planned shutdowns. Second, the field-service workflow does not require precision laser alignment \u2014 a major scheduling advantage during the constrained shutdown windows typical of continuous-production plants.<\/p>\n

For OEM equipment builders, these architectural advantages translate directly into reduced warranty exposure and improved customer-experience metrics. For end-user plants, they translate into reduced maintenance-management overhead. The combined value proposition has kept the SL240 on equipment specifications across multiple equipment generations. See Ever-power’s engineering portal<\/a> for related selection materials.<\/p>\n

\"SL240<\/p>\n

Industry Applications<\/h3>\n
\n
\n

<\/span> Cement-Mill Main Drives<\/h4>\n

Drive coupling between motor and reduction-input of cement-grinding mills. Cast-iron section and gradual failure mode are the architectural fit for continuous-production cement operations.<\/p>\n<\/p><\/div>\n

\n

<\/span> Hot-Strip-Mill Auxiliary<\/h4>\n

Roughing-stand auxiliary, edger-mill drive, and finishing-stand support drives in hot-strip rolling mills. Elevated-temperature cast-iron tolerance addresses the demanding ambient of hot-mill operation.<\/p>\n<\/p><\/div>\n

\n

<\/span> Hydropower Auxiliary Trains<\/h4>\n

Gate-actuator, trash-rake, and governor-aux drives on small-to-medium hydropower installations. Long-cycle reliability across decades of duty.<\/p>\n<\/p><\/div>\n

\n

\ufe0f<\/span> Heavy Process Pumps<\/h4>\n

Large centrifugal, gear, and lobe-pump drives in petrochemical, fertiliser, and process-chemical installations. Misalignment tolerance absorbs thermal-growth between cold-start and operating-temperature states.<\/p>\n<\/p><\/div>\n

\n

\u26cf\ufe0f<\/span> Mining Conveyor Head Drives<\/h4>\n

Drive-end coupling on heavy overland and underground mining conveyors. Shock-load tolerance addresses the inrush profile of conveyor start under loaded conditions.<\/p>\n<\/p><\/div>\n

\n

<\/span> Large Marine Winches<\/h4>\n

Anchor-winch and mooring-winch drives on commercial vessels and dredging fleet. QT500 ductile-iron hubs and calcium-sulfonate grease resist saltwater ambient.<\/p>\n<\/p><\/div>\n<\/div>\n

Why Choose Ever-power<\/h3>\n
\n

Quality & Compliance<\/h4>\n

SL240 production runs under ISO 9001:2015<\/strong> with full melt-traceability per cast-iron heat. Documentation covers RoHS<\/strong>, REACH<\/strong>, and CE<\/strong> conformity declarations. For cement-plant customers, supplementary documentation covering dust-class compatibility of standard and synthetic grease specifications is available. For steel-mill customers, additional thermal-cycle endurance documentation is supplied on request.<\/p>\n

Customisation<\/h4>\n

Catalogue bore range 95\u2013100 mm; oversized variants up to 105 mm produced under engineering review. Imperial-bore variants (3-3\/4″, 3-7\/8″, 4″) supported for North American export markets. QT500-7 ductile-iron hub is the standard recommendation at this size; HT250 variant available for cost-sensitive light-duty applications. Taper-bushed mounting via standard locking-assembly families is the documented best practice for cement, steel-mill, and crusher installations.<\/p>\n

Aftermarket<\/h4>\n

SL240 slider plates stocked under part SL240-SLIDER for 2-business-day shipment. 40Cr alloy slider available within 1 week. Mass per coupling 59.5 kg; sea-freight standard in heavy-duty crating. English-speaking engineering desk responds within 24 hours<\/strong>. For continuous-production customers, emergency-replacement protocols can be pre-negotiated to support major-plant shutdowns within 5 working days.<\/p>\n<\/div>\n

\"Ever-power<\/p>\n

Customer Reviews & Case Studies<\/h3>\n
\n
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\u2605\u2605\u2605\u2605\u2605<\/p>\n

Sri Lanka \u2014 Cement-Production Facility<\/h4>\n

Used in:<\/em> Cement-mill main drive coupling on a 75 t\/h vertical roller mill installation.<\/p>\n

Feedback:<\/em> “Specified SL240 with QT500 hubs and taper-bushed mounting as a replacement for the original gear-coupling spec. Five years of continuous-production duty with zero coupling-attributable downtime events. Annual mill availability has improved measurably as a result of removing the gear-coupling-related downtime that had been a recurring incident category.”<\/p>\n<\/p><\/div>\n

\n

\u2605\u2605\u2605\u2605\u2605<\/p>\n

Bangladesh \u2014 Steel Re-rolling Mill<\/h4>\n

Used in:<\/em> Edger-mill auxiliary drive coupling on a hot-strip re-rolling operation.<\/p>\n

Feedback:<\/em> “Elevated-temperature ambient (60+ \u00b0C continuous) had been challenging for every flexible-coupling architecture we tried. The SL240 with synthetic high-temperature grease has now passed 4 years of continuous duty with one slider replacement during a planned mill overhaul. Cast-iron hubs show no measurable change in dimensional accuracy. Excellent specification for hot-mill auxiliary duty.”<\/p>\n<\/p><\/div>\n

\n

\u2605\u2605\u2605\u2605\u2606<\/p>\n

Mongolia \u2014 Mining-Site Conveyor Operator<\/h4>\n

Used in:<\/em> Drive-end coupling on a 1 200 mm wide overland coal conveyor.<\/p>\n

Feedback:<\/em> “Inrush torque on loaded-conveyor start regularly exceeds 1.5\u00d7 rated. The QT500-hub SL240 has handled this for 5 years with one slider replacement during a planned mine-site shutdown. Annual grease repack is the only routine maintenance touch point. Knock one star only because emergency air-freight shipment to our remote site location was logistically challenging during one urgent replacement event \u2014 eventually resolved but took an extra 4 days.”<\/p>\n<\/p><\/div>\n<\/div>\n

Frequently Asked Questions<\/h3>\n
\nIs QT500 ductile-iron really the standard recommendation at this size?<\/summary>\n

Yes. At SL240 size and above, the engineering case for ductile iron over grey iron becomes unambiguous: the 3\u00d7 higher fracture toughness translates directly into shock-load endurance that grey iron cannot match. For cement, steel-mill, mining, and crusher installations the QT500 variant is the documented standard specification. Grey iron remains available for cost-sensitive light-duty applications, but its use should be limited to low-shock-load duty profiles.<\/p>\n<\/details>\n

\nWhat is the recommended hot-mill ambient grease specification?<\/summary>\n

For continuous ambient between +80 \u00b0C and +150 \u00b0C (typical of hot-strip-mill auxiliary deployments), specify synthetic polyalphaolefin grease (e.g., Kl\u00fcber Asonic GHY 72-72). This grease maintains its viscosity profile across the temperature range, resists oxidation, and remains compatible with the cast-iron and steel sliding interfaces. Grease-repack interval at this temperature range is 4 months.<\/p>\n<\/details>\n

\nHow does the SL240 compare to a flexible disc-pack at this rating?<\/summary>\n

At the 8 000 N\u00b7m torque rating, flexible disc-pack couplings offer slightly lower mass (typically 45 kg vs the SL240’s 59.5 kg) but require precision laser-alignment for service-life predictability and offer roughly 1\/10th the parallel-misalignment tolerance. For continuous-production plants where reliability and serviceability are paramount, the SL240’s lifecycle-cost economics are clearly favourable.<\/p>\n<\/details>\n

\nWhat is the typical planned-shutdown slider-replacement time?<\/summary>\n

For a trained maintenance crew, total time to replace the SL240 slider is approximately 90 minutes including documentation: 15 minutes to remove the coupling guard and inspect, 30 minutes to remove old slider and clean the slot interfaces, 30 minutes to fit the new slider and re-grease, and 15 minutes to refit the coupling guard and finalise documentation. This is well within the constrained shutdown windows of continuous-production plants.<\/p>\n<\/details>\n

\nAre emergency-replacement protocols pre-arrangeable?<\/summary>\n

Yes. For continuous-production customers, Ever-power offers pre-negotiated emergency-replacement protocols that guarantee 5-working-day delivery of replacement SL240 couplings or slider plates from confirmed PO. Air-freight logistics are pre-arranged to the customer’s nominated logistics hub. Programme terms are negotiated with the sales desk based on installed-base size and historical demand profile.<\/p>\n<\/details>\n

Quote SL240 for Critical-Path Drives<\/h3>\n

For cement-mill main, steel-mill auxiliary, hydropower-aux, and heavy process-pump installations in the 150\u2013210 kW power class, the SL240 has been Ever-power’s reliability standard for continuous-production-plant duty. Browse the wider SL series catalogue<\/a>, read about Ever-power’s heavy-industrial supply commitments<\/a>, or move directly to enquiry below.<\/p>\n

\n Quote SL240 Now \u2192<\/a>\n<\/p>\n